As it has since 1999, airline ratings service Skytrax has published the results of its 2014 World Airline Survey, ranking more than 200 of the world’s airlines from best to worst. The rankings were based on responses to 18.9 million customer surveys.

Skytrax boasts that it uses sophisticated data-weighting algorithms to compensate for different sample sizes, and has fraud-detection mechanisms in place to maintain the results’ legitimacy. And the research is not funded by any of the ranked companies.

Although the survey is clearly more rigorous than most, there are questions about its methodology. It’s not clear, for example, how much weight is given to the various factors that, taken together, give an airline its overall score. Full transparency is reserved for airline executives, who presumably pay for privileged access.

The top-20 airlines, according to the latest survey, are as follows:

Cathay Pacific Airways

Qatar Airways

Singapore Airlines

Emirates

Turkish Airlines

ANA All Nippon Airways

Garuda Indonesia

Asiana Airlines

Etihad Airways

Lufthansa

Qantas Airways

EVA Air

Swiss

Thai Airways

Virgin Australia

Air New Zealand

British Airways

Malaysia Airlines

Hainan Airlines

Bangkok Airways

Conspicuously missing from the list of top airlines are any carriers from North America. Among themselves, they were ranked as follows:

Air Canada

WestJet

Virgin America

Delta Air Lines

United Airlines

Porter Airlines

JetBlue Airways

Alaska Airlines

Southwest Airlines

American Eagle Airlines

In case you were wondering, only one airline scored just a single star in the Skytrax system, which awards a maximum of five stars: North Korea’s Air Koryo.